A. Fornalczyk

Vapour Treatment Method Against Other Pyro-and Hydrometallurgical Processes Applied to Recover Platinum From Used Auto Catalytic Converters

Today more and more cars are produced every year. All of them have to be equipped with catalytic converters, the main role of which is to obtain substances harmless to the environment instead of exhausted gases. Catalytic converters contain platinum group metals (PGM) especially platinum, palladium and rhodium. The price of these metals and their increasing demand are the reasons why today it is necessary to recycle used auto catalytic converters. There are many available methods of recovering PGM metals from them, especially platinum. These methods used mainly hydrometallurgical processes; however pyrometallurgical ones become more and more popular. The article presents results of the research mainly concerning pyrometallurgical processes. Two groups of research were carried out. In the first one different metals such as lead, magnesium and copper were used as a metal collector. During the tests, platinum went to those metals forming an alloy. In other research metal vapours were blown through catalytic converter carrier (grinded or whole). In the tests metals such as calcium, magnesium, cadmium and zinc were applied. As a result white or grey powder (metal plus platinum) was obtained. The tables present results of the research. Processing parameters and conclusions are also shown. To compare efficiency of pyrometallurgical and hydrometallurgical methods catalytic converter carrier and samples of copper with platinum obtained from pyrometallurgical method were solved in aqua regia, mixture of aqua regia and fluoric acid.

Selective Recovery Of Copper From Solutions After Bioleaching Electronic Waste

Abstract Research on selective extraction of copper from solution after bioleaching grounded printed circuit boards (PCBs) using LIX 860N-IC were conducted. The effect of LIX 860N-IC concentration, phase ratio and influence of initial pH value of aqueous phase on the extraction of copper and iron was examined. It was found that the extraction rate of copper increases with the LIX 860N-IC concentration. Best results of Cu extraction (98 %) were achieved with extractant concentration of 5 % and pH 1.9. Higher pH value of aqueous phase (pH=2.4) is conducive to the simultaneous effect of Fe co-extraction.

Model of Infiltration of Spent Automotive Catalysts by Molten Metal in Process of Platinum Metals Recovery

This paper presents the model for the washing-out process of precious metals from spent catalysts by the use of molten lead in which the metal flow is caused by the rotating electromagnetic field and the Lorentz force. The model includes the coupling of the electromagnetic field with the hydrodynamic field, the flow of metal through anisotropic and porous structure of the catalyst, and the movement of the phase boundary (air-metal) during infiltration of the catalyst carrier by the molten metal. The developed model enabled analysis of the impact of spacing between the catalysts and the supply current on the degree of catalyst infiltration by the molten metal. The results of calculations carried out on the basis of the model were verified experimentally.

Corrosion Resistance of ZnAlMg Alloys for Batch Hot Dip Galvanizing

In the paper the results of corrosion resistance tests on ZnAlMg alloys used as batch hot dip galvanizing baths are presented. The tests were carried out on ZnAl alloys with 7 wt.% Al with the addition of 3 wt.% and 6 wt.% Mg. Corrosion resistance of tested alloys was compared with corrosion resistance of the traditional zinc bath alloy. Corrosion resistance of the alloys was defined by comparative methods in two standard corrosion tests in neutral salt spray and in moist atmosphere containing SO2. Electrochemical parameters of the corrosion process were determined on the basis of potentiodynamic tests. It was determined that the alloy of ZnAl7 has better corrosion resistance than the corrosion resistance of the alloy of a traditional zinc bath and that the addition of Mg to the alloy increases the corrosion resistance.

Modelling Methods of Magnetohydrodynamic Phenomena Occurring in a Channel of the Device Used to Wash out Spent Automotive Catalyst on Metallic Substrate by a Liquid Metal

The recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material because as the devices. they have to be periodically renovated and eventually replaced. Among automotive catalysts withdrawn from use, these with metallic carrier constitute quite a big group. Metallic carriers are usually obtained from steel FeCrAl , which is covered by a layer of PGM acting as a catalyst. World literature describes a number of pyro-or hydrometallurgical methods used for recovery of platinum from used automobile catalytic converters. However, all methods, available in the literature, are used to recover platinum from ceramic carrier. This paper presents the new method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out platinum by using mangetohydrodynamic pump. The article includes the description of the methods used in modelling magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields) occurring in this particular device for this kind of waste. The general phenomena and ways of coupling the various physical fields for this type of calculation have also been described. The basic computational techniques with a discussion of their advantages and disadvantages have been presented.

The Morphology of Corrosion Products in FeAl Alloys after Heat-Resistance Tests at Different Temperatures

The alloys based on intermetallic phases involving Al belong to a new group of heat-resistant materials. Their physico-chemical and mechanical properties allow to apply them in the operating conditions in corrosive environment and elevated temperature. Research conducted for many years has shown that these materials can work at temperature up to 1100°C without degradation of their occurrence in the environment containing oxygen and sulphur. Heat resistance of these materials is provided by forming the Al2O3 passive layer on the surface. This layer is a protective barrier, which hinders the oxygen diffusion into the surface. This paper presents the morphology of passive Al2O3 layer depending on the temperature of its formation. The study allows to define the surface condition for corrosion products carried out using scanning electron microscopy together with EDS X-ray microanalysis.